She wrote in Arabic: “The first British ambassador to the Kingdom leads the pilgrimage after his conversion to Islam: Simon Collis with his wife Mrs Huda in Mecca. Praise be to Allah.”

Collis thanked her in a tweet.

The ambassador converted to Islam in 2011 “after spending 30 years in Muslim societies” and shortly before his marriage to Huda al-Mujarkech, according to Arab media reports.

Collis has been based in Riyadh since 2015. He previously served in a number of Middle Eastern countries, including Syria, Iraq, Qatar, United Arab Emirates and Yemen, as well as in India and Tunisia.

The Foreign Office declined to comment, saying it was a private matter. The British embassy in Riyadh also said it had no comment.

An estimated 1.8 million Muslim pilgrims completed the hajj this year at holy sites in Saudi Arabia. The hajj is one of the five pillars of Islam, and able-bodied Muslims are expected to make the pilgrimage at least once in their lives.